NCIS: Hawaii Episode 1.07 Rescuers

When a Naval officer is killed the team investigates and looks for his girlfriend, a CoastGuard rescue swimmer who disappeared. They find her having returned from a camping trip and when they enter her home , what they see creeps the woman. And she doesn't want to say what's going on. They learn in her youth she was tight with a gang leader who does some despicable things. When they confront her with it. She admits the guy was responsible for some deaths and expected her to be his alibi but she couldn't so he was sent to prison. He was released and is on the island and when they find him he has an alibi. So they promise the girl they will do what they can to take him down but she's afraid.